He said: “Knightley and McAvoy have surely clinched their place as world-class lead actors.”

He predicted Atonement will figure strongly in the awards season and described it as “a startlingly fine piece of movie-making, one that elevates its director Joe Wright to the international pantheon”.

James Christopher, in The Times, wrote: “Working with Wright has opened up Knightley’s acting; the range of her performance here means that she has a tilt, at least, at an Oscar nomination.”

But Christopher went on to say the film became a “grim slog” after a strong start.

Geoffrey McNab, for the Independent, said: “The strength of the film lies in its extraordinary visual imagination and in the intensity the young actors bring to their roles.”

Christopher Tookey, in the Daily Mail, said “the film is always gripping” but said Knightley’s performance as Cecilia Tallis might be too “brittle, unpleasant and snobbish” to gain the sympathy of viewers.